I want to create a document and use headers that count up with a custom field. I want to count using Step 1, Step 2, Step 3, etc. They don't have to be headers, I just need to count up using the prefix "Step". Can someone point me to a place that shows me how to do this? Thanks.

A PAGE field in the header will increment on every page. A SECTION field in the header will increment on every new Section (which can span multiple pages). You can prefix either with the typed string 'Step '.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]

For that matter, a SEQuence Field can count up. You could enclose it in a calculation field to step it.

Start numbering at 1, step 7:
{ = 1 + {SEQ MySeq } * 7 - 7 }
This will give you: 1, 8, 15, 22...

Oops, misunderstood "step." Could still use a SEQ field. Put "Step { Seq MySeq }" in an AutoText entry.

But, why not simply use Automatic numbering linked to styles?
How to create numbered headings or outline numbering in Ribbon Versions of Word by Shauna Kelly